Force Control - Festo CPX Series Manual

3. Drive functions

3.1.2 Force control

Festo P.BE−CPX−CMA X−CONTROL−EN en 0908NH
Force control is done by controlling the pressure forces which
act on the piston in both cylinder chambers. The force of the
cylinder is not controlled directly a force sensor would be
required for this but is controlled via the force acting on the
piston. The imprecision of the force is therefore in the range
of the static friction force of the drive. The setpoint values are
specified as a force in the used system of units. The force on
the piston to be regulated is determined via the force set
point, the mounting position, the mass and the piston rod
diameter. The force controller is parametrised automatically
depending on the set project data, so that the controller para
meters can remain at their default values in the normal case.
Properties:
Setpoints and tolerance are specified as forces.
Path / speed monitoring during force control.
Stop behaviour: Setpoint position is identical to the actual
position.
Force ramp (modification speed) can be set.
The force signaled as the actual force does not include
gravity as long as the workpiece mass was given correctly
in the positioning task.
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